第19卷第5期 2011年5月
文章编号
1004-924X(2011)05-1030-09
光学精密工程
Optics and Precision Engineering
金属微粉体脉冲输送的微特性实验
侯丽雅1：，王振琪"，章维1，杨眉1，林峰（1.南京理工大学机械工程学院，江苏南京210094；
2.清华大学机械工程系，北京100084）
Vol.19No. 5
May 2011
摘要：采用以脉冲为微流动基本形态、脉冲当地惯性力为主动力的微流体数字化技术进行了金属微粉体(作为流体)脉冲输送微特性的实验，以解决激光金属粉体融覆沉积工艺中微粉体的精确稳定输送问题。建立了金属微粉体脉冲输送系统；以角形铬粉为实验材料，实验研究了驱动电压U、率了、微喷嘴内径d、输送角度9等4种系统参量对铬粉脉冲输送微特性（粉体输送率和输送稳定性)的影响规律；以此规律为依据，确定和选择铬粉脉冲输送的系统参量，验证粉体微输送效果。实验显示，金属微粉体脉冲输送系统具有精确稳定的脉冲输送微特性，表征输送稳定性的变异系数C，V< 7%，铬粉输送率Q可达每秒儿十微克量级。结果表明；微流体数字化技术可实现金属微粉体的脉冲精确稳定输送；提出
的研究方法可用于不同工程应用背景的微粉体脉冲输送的理论和实验研究，关键调：脉冲输逐；粉体输送；微特性；微流体数字化；激光粉体熔融况积
中图分类号：TG156.99
文献标识码：A
doi;10, 3788/OPE, 20111905. 1030
Experimentsofmicrocharacteristicsof pulse-transfer formicro metallic powders
HOU Li-ya'·,WANG Zhen-qi',ZHANG Wei-yi',YANG Mei',LIN Feng
(l.School of Mechanical Engneering,Nanjing University o
Science and Technology, Nanjing 210094, China;
2.DepartmentofMechanicalEngineering,TsinghuaUniversity,Beijing100084,China)
*Correspondingauthor,E-mail;hou_liya@hotmail.com
Abstract: To achieve the stable and precise transfer of micro metallic powders in the laser microclad-ding fabrication,the micro characteristics of micro metallic powder transfer, called pulse-transfer, are studied based on a new principle of microfluidic drive and control, in which microfluidic flows are driv en by the pulsed local inertia force in micro channels. By using this technique, the flow of microfluid-ics can be controlled in pulse (or digital) demands. An experimental system of pulse-transfer for micro metallic powders is built to determine influencing rules of four system parameters, voltage amplitude U, frequence f, the inner diameter d of micro-nozzle, and the angle of transfer , on micro character-istics (powder transfer rate and stablity) of irregular micro chromium powders. The system parame-ters are optimized according to the influencing rules for transferring irregular micro chromium pow-
收稿日期：2010-06-23；修订日期：2010-09-14.
基金项目：国家自然科学基金资助项目（No.50975152)；南京理工大学自主科研专项计划资助项目（No.
2010GJPY006)；教育部博士学科点专项科研基金资助项目（No.20060288005）